# US 2008/0185418 A1 · Multistage solenoid fastening device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0185418 A1 - Document ID: US20080185418A1 - Status: Published application - Kind: A1 - Application number: 11/670,088 - Filed: 2007-02-01 - Published: 2008-08-07 - Earliest claimed: 2007-02-01 - Assignees: Black & Decker Inc. - Inventors: Paul G. Gross; Nathan J. Cruise - Web page: https://patentgrep.com/patent/US20080185418A1 ## CPC - B25C 1/06: operated by electric power - B25C: HAND-HELD NAILING OR STAPLING TOOLS; MANUALLY OPERATED PORTABLE STAPLING TOOLS (for shoemaking A43D) ## Abstract A fastening device drives one or more fasteners into a workpiece. The fastening device generally includes a tool housing and a multistage solenoid having at least a first stage, a second stage and an armature member that travels therebetween. The multistage solenoid is contained within the tool housing. A driver blade is connected to the armature member. The driver blade is operable between an extended condition and a retracted condition. A control module determines a position of the armature member relative to at least one of the first stage, the second stage and a combination thereof. A trigger assembly is connected to the control module and activates a driver sequence that moves the driver blade member between the retracted condition and the extended condition. The control module directs power between the first stage and the second stage based on the position of the armature member relative thereto. ## Claims ### Claim 1 A fastening device that drives one or more fasteners into a workpiece, the fastening device comprising: a tool housing; a multistage solenoid having at least a first stage, a second stage and an armature member that travels therebetween, said multistage solenoid contained within said tool housing; a driver blade member connected to said armature member, said driver blade member operable between an extended condition and a retracted condition; a control module that determines a position of said armature member relative to at least one of said first stage, said second stage and a combination thereof; and a trigger assembly connected to said control module that activates a driver sequence that moves said driver blade member between said retracted condition and said extended condition, wherein said control module directs power between said first stage and said second stage based on said position of said armature member relative thereto. ### Claim 2 (depends on 1) The fastening device of claim 1 wherein said control module determines said position of said armature member by determining a change in current associated with at least one of said first stage, said second stage and said combination thereof, said change in said current caused by a change in an inductance of a circuit associated with said at least one of said first stage, said second stage and said combination thereof. ### Claim 3 (depends on 1) The fastening device of claim 1 wherein said control module determines said position of said armature member based on a detection of a current inflection point associated with one of said first stage and said second stage. ### Claim 4 (depends on 1) The fastening device of claim 1 wherein said control module determines said position of said armature member by communicating with one or more sensors that detect said position of said armature member, said one or more sensors associated with at least one of said first stage, said second stage and said combinations thereof. ### Claim 5 (depends on 1) The fastening device of claim 1 wherein said control module collapses a magnetic field associated with said first stage and establishes a magnetic field with said second stage when said control module detects a first current inflection point. ### Claim 6 (depends on 1) The fastening device of claim 1 wherein said armature member and said driver blade member are a single member. ### Claim 7 (depends on 1) The fastening device of claim 1 wherein said armature member moves to said extended condition to strike a portion of said driver blade member to move said driver blade member from said retracted condition to said extended condition. ### Claim 8 (depends on 1) The fastening device of claim 1 further comprising a spring member connected to said driver blade member, wherein said driver blade member moves against a bias of said spring member when moving from said retracted condition to said extended condition. ### Claim 9 (depends on 8) The fastening device of claim 8 wherein only said spring member moves said armature member from said extended condition to said retracted condition and only at least one of said first stage, said second stage and said combination thereof move said armature member from said retracted condition to said extended condition. ### Claim 10 (depends on 1) The fastening device of claim 1 further comprising a spring member connected to said armature member, wherein said armature member moves against a bias of said spring member when moving from said retracted condition to said extended condition. ### Claim 11 A device comprising: a multistage solenoid having at least a first stage, a second stage and an armature member that travels therebetween; and a control module connected to said multistage solenoid, wherein said control module detects a position of said armature member relative to at least one of said first stage, said second stage and a combination thereof and wherein said control module adjusts a magnetic field of said at least one of said first stage, said second stage and said combination thereof based on said position of said plunger member relative thereto. ### Claim 12 (depends on 11) The device of claim 11 wherein said control module determines said position of said plunger member by determining a change in a rate of current associated with at least one of said first stage, said second stage and said combinations thereof and wherein said change in said rate of said current is caused by a change in an inductance of a circuit associated with said at least one of said first stage, said second stage and said combinations thereof. ### Claim 13 (depends on 11) The device of claim 11 wherein said control module determines said position of said armature member based on detection of a current inflection point associated with one of said first stage and said second stage. ### Claim 14 (depends on 11) The device of claim 11 wherein said control module determines said position of said armature member by communicating with one or more sensors that detect said position of said armature member and wherein said one or more sensors are associated with at least one of said first stage, said second stage and said combination thereof. ### Claim 15 (depends on 11) The device of claim 11 wherein said control module collapses or establishes said magnetic field associated with at least one of said first stage, said second stage and said combination thereof based on said position of said armature member relative thereto. ### Claim 16 A method of driving a fastener into workpiece, the method comprising: retracting a trigger to execute a driver sequence; establishing a magnetic field in a multistage solenoid, wherein said magnetic field is established in at least one of a first stage, a second stage and a combination thereof; drawing an armature member to an extended condition from a retracted condition with said magnetic field; determining a position of said armature member relative to at least one of said first stage, said second stage and said combination thereof; and directing power between said first stage and said second stage during said driver sequence, wherein said directing of said power is based on said determining of said position of said armature member. ### Claim 17 (depends on 16) The method of claim 16 wherein said determining of said position of said armature member includes determining a change in a current associated with at least one of said first stage, said second stage and said combination thereof, wherein said change in said current is caused by a change in an inductance of a circuit associated with said at least one of said first stage, said second stage and said combination thereof. ### Claim 18 (depends on 16) The method of claim 16 wherein said determining of said position of said armature member includes detecting a current inflection point associated with one of said first stage, said second stage and said combination thereof. ### Claim 19 (depends on 16) The method of claim 16 wherein said determining of said position of said armature member includes communicating with one or more sensors that detect said position of said armature member. ### Claim 20 (depends on 16) The method claim 16 further comprising moving a driver blade member from a retracted condition to an extended condition when said armature member moves from said retracted condition to said extended condition. ### Claim 21 (depends on 20) The method of claim 20 further comprising striking a portion of said driver blade member with said plunger member to move said driver blade member from said retracted condition to said extended condition. ### Claim 22 (depends on 16) The method of claim 16 further comprising moving said plunger member from said extended condition to said retracted condition with only a force generated by a spring member.